class Container{
    static of(value){
        return new Container(value)
    }

    constructor(value){
        this._value = value
    }

    map(fn){
        return Container.of(fn(this._value))
    }
}

class Maybe{
    static of(x){
        return new Maybe(x)
    }

    constructor(x){
        this._value = x
    }

    isNothing(){
        return this._value === undefined || this._value === null
    }

    map(fn){
        return this.isNothing() ? this : Maybe.of(fn(this._value))
    }
}

module.exports = { Maybe, Container }